Foreshortening of the inferior conjunctival fornix associated with chronic glaucoma medications.

The authors designed a device to measure the depth of the inferior conjunctival fornix at the slit lamp using topical anesthesia. The fornices of 179 glaucoma patients receiving topical medications for glaucoma and 420 control subjects who had no history of ocular disease were measured. These measurements were age-stratified by decade. A significant foreshortening of the inferior conjunctival fornix was found with aging (P less than 0.01). Patients in their sixth through ninth decades using miotics for 3 years or longer and patients using nonmiotic agents for 3 years or longer exhibited significant foreshortening of the inferior fornix when compared with age-stratified (by decade) control subjects (P less than 0.01). These observations suggest that increasing age and topical medications for glaucoma, or the preservatives, used for 3 years or longer, are independently associated with conjunctival shrinkage.

The anatomy of the lateral canthal tendon.

This report documents the anatomy of the lateral canthus using gross dissection, histologic examination, computed tomography, magnetic resonance imaging, and clinical measurement. Lateral canthal dissections of 16 cadaver orbits demonstrated a well-defined attachment of the tarsal plates to the orbital rim, averaging 10.6 mm in length and 10.2 mm in width at their insertion on Whitnall's tubercle, 1.5 mm behind the orbital rim and 9.7 mm inferior to the frontozygomatic suture. Histologic examination showed a band of dense fibrous tissue attached to the tarsal plates, with intermingled muscle fibers from the pretarsal orbicularis oculi muscle. A small pocket of fat was identified posterior to the orbital septum and anterior to the lateral canthal tendon. Clinical measurements of normal adults revealed 2 mm of lateral movement of the canthal angle during abduction, apparently caused by posterior fibrous attachments to the check ligament of the lateral rectus muscle.